The Problem With Astrophysicists
by impossibilitiesandmiracles
Summary: So the thing about scientists—rocket scientists in particular—is that they are obsessive. Science is an addiction. Even if it's been 3700 years and all technology is basically void, they just can't help themselves. Really, it was only a matter of time before Senku felt that restlessness in his fingertips. It was only a matter of time before he absolutely had to build a rocket.


**The Problem With Astrophysicists **

_everything you can imagine is real_ -Picasso

Despite having to completely rebuild society from the ground up, and create technology, and make discoveries that had already been made, and produce medicine from scratch, not to mention reinvent navigation because it had been long enough for astronomical bodies to move just enough to be inconvenient—despite all of that, Senku was bored. Because honestly genius is always a little bored.

There were no books to read. Someone had to write them (again), but Senku and Chrome were too busy making the content to worry if anyone was actually writing this stuff down. There were no robots to tinker with, nothing to take apart and put back together. Senku was ten billion percent sure that if he didn't do something even mildly intellectually stimulating just for the fun of it, he was going to lose his mind.

(He'd done enough inventing for eight lifetimes. They had been working two million years of human evolution into a year and a half. But the experiments they conducted weren't to figure out an answer, because he already knew all the answers. He already knew how it was going to turn out.)

It had been too long since he'd asked a question, too long since he'd done something out of curiosity instead of necessity.

It had been too goddamn long since he built a rocket.

And, I mean, really it was only a matter of time.

It was very logical once you thought about it. And besides, he was getting just a little tired of being the leader. For just this moment Senku didn't want to be the patriarch of civilization, he just wanted to be a scientist. Right now, he wanted to pretend that space wasn't so far away.

Maybe there were a million other things to do, and Senku was sure that the kingdom of science was nowhere near the common era, but it could wait. They had waited 3700 years and they could wait one more afternoon so Senku can indulge his astrophysics addiction.

"I'll be back later," he said, waving his hand distractedly as he left the laboratory. Gen shot him a look.

"Where—"

"Out," Senku didn't look back, "I'll be back by sunset." Gen said a skeptical goodbye but didn't press further.

He walked in some direction for some amount of time which in all honesty he was too distracted to keep track of. Finally he came to a quiet place where he could think. He could think and think and think all day long about the rocket he was going to build, the one that would eventually get him to space.

But that was a long ways off, and he had to start somewhere.

Senku had made a list in his head forever ago about the things he'd need to build a small working model about as tall as he was. He had everything he needed, he just…had to actually put them in order, and use them constructively. The engine would be the toughest, if he wanted it to work properly that it is. Anyone can make a silly little pressure reaction to shoot something a few feet in the air, but a rocket engine needed to be more powerful. And he'd need an ion engine if he hoped to get past the tree line.

"A rocket in the Stone Age," Senku muttered to himself. "This is exhilarating."

The actual body of the rocket wasn't too hard to make. They'd already gone through the process while making the car, and then the carbon fiber polymer from the shield, so recycling parts for a rocket was simple. Senku used excess carbon fiber to make the cone and body, then attached the fins. It was hard to get just the right angle, especially since he wasn't investing all of his tools and manpower, but the direction didn't matter too much in this experiment—the goal was just for it to launch.

Anyway, building the body of the rocket was fun. It reminded him of all those thousands of years ago when he'd done this too many times to count. He enjoyed it every bit as much as he did back then.

Senku was building and unbuilding and rebuilding again. And it felt a lot like his first few days when he'd been unpetrified. To the untrained eye it might not look like he was doing much. But he supposed progress never really looked like much at first, and then there was that wonderful moment when it all snapped into place. He lived for those moments.

_Learn. Build. Rebuild. Keep learning, keep growing and never stop._

That was engineering.

That was science.

It was exactly what he needed right now.

And Senku was happy. Completely over the moon, actually.

You see, it was just the sheer enjoyment of science that got his blood pumping. He didn't need to meet any deadline or worry about a height requirement or whether or not it exploded once it left the atmosphere, it was just science for the sake of science. And that was his favorite kind.

(Because isn't that was it's really about?)

"Senku!" Suika called from over his shoulder. "What are you building?"

"A rocket," he explained, "It's a spaceship that goes all the way up past the sky. In the past NASA used to build all different kinds that would make maps of the stars, or collect samples from other planets. Some people even wanted to see if there was life beyond our solar system." Senku smiled sadly. "Though, I doubt this one will even make it to the stratosphere."

There was a pause and then—"Wow! That's amazing. You mean it goes even higher than a hot air balloon?"

"That's right."

"That—that's amazing!" She leaned in closer, "Promise you'll let me see it when you're done. Don't let it fly away until I can see it."

"Sure," he promised, "I won't launch without you."

"I can't wait," Suika said happily.

She hung around for a little while longer, but Senku was too focused to notice when she left.

The ion engine was a bit tough, per his hypothesis. Even with all the other chemical compounds he'd made, which were about ten billion times more difficult, getting the reaction within a fractional percent error margin was still going to be tricky (I mean, give him a break, it's been 3700 years since he messed around with rocket fuel). It wasn't as touchy as nitroglycerin, but it could still blow up in his face if he didn't get it right.

But more important than that, if Senku didn't get the correct proportion then the rocket would either not launch, or the engine would burn out too quickly and explode in the atmosphere. He knew this rocket was bound to blow up eventually, considering the half assed job he was doing, but he was going to make sure to push its limits before that happened.

And to be honest, it would be more heartbreaking if it didn't launch than if he got blown up. Senku could still remember the sinking feeling in his stomach every time one of his rockets didn't launch because of some mathematical error. It hurt. It reeked of failure. But the exhilaration he felt from succeeding...well that was ten billion percent worth the risk. It was the best feeling in the world.

And it had been so long since he'd felt it.

Senku shook his head. _Don't dwell on the past_, he told himself, _just stride towards the future, and feel it again._

Luckily all the parts for the ion engine were already acquired. He had the aluminum set and ready to go thanks to Chrome's collecting skills. Then he mixed together perchloric acid stored in the laboratory with ammonia to make—you guessed it!—ammonium perchlorate!

Note for all you non-rocket science enthusiasts: The reaction between aluminum (one of the most abundant and highly reactive elements on earth) with ammonium perchlorate creates the rocket fuel needed to launch.

Senku figured he'd need about two of the boosters considering the size of his rocket and the expectations he had for it. Granted the whole thing was scaled down to be only a foot or so taller than him, and was nowhere near the size of the rockets he used to build. But he didn't really think he had enough materials to make that anyway (considering he'd used a shit ton of aluminum already).

There's something you should know about all scientists, but especially astrophysicists. It is not a phase, it is a lifestyle. The moment you're hooked on rocket science or aeronautical engineering or astrophysics, you will never be able to let go of that feeling. Senku has felt it ever since he was little. That feeling of being a part of something so much bigger than yourself.

You feel like the tiniest thing in the universe. You feel like something more than human, like something cosmic and ageless and there is no better high.

It's an important distinction to make, the one between a hobby and an addiction. He'd crossed that line a long time ago. In fact, if he thought about it, Senku had probably bound over that line at terminal velocity, no hesitation at all. Because that's the thing about astrophysicists, they're addicts. And they'll tear apart galaxies to get their next fix.

That feeling of being a part of something so much bigger than yourself, being infinite for one moment and finally understanding what it is to _exist_—that feeling, well, Senku is pretty damn sure that's what home feels like. And he's like all the rest of them, rushing endlessly forward insearch of the next high.

(All scientists are addicts, you know. It's the addiction that drives them to explore every possible outcome. It's what creates progress; and without it humanity would have withered away like stone.)

Another important thing to know about scientists is that despite how observant they are, all of that goes away when they're experimenting. Any sensory input from the outside world just doesn't register. So it's no surprise Senku didn't hear Chrome coming up behind him.

"Senku!"

He startled, whipping his head around to look at the other boy, and almost spilling the rocket fuel. "What, Chrome?"

"Look at what I made," Chrome held out a backpack that had a cloth inside, "Surprised? If you fall out of the hot air balloon I was thinking about how to keep us safe. This thing solves all our problems, you just pull this string to release a smaller balloon to slow your descent. I call it—"

"It's a parachute."

Chrome looked visibly dejected that Senku had a name for his so-called mystery object but quickly recovered when he saw the rocket.

"What kind of motor is that?" Chrome asked, "Suika told us you were making a rocket. I figured it would look like that gorilla car but...how's it going to move?"

"It's an ion engine," Senku said, "The reaction between the metal and chemical compound forces electrons to break apart and form new bonds. An ion is an element that has either lost electrons or gained them and now has a charge. Oxidation is the process of losing electrons and reduction is gaining one. They always come as a pair called a redox reaction.

"NASA used it to power their ion engine and launch some of their rockets. It's pretty simple to calibrate down to the level I need. The redox reaction in the engine will boost the rocket ship a few kilometers into the air. If I had more stuff I could probably get it all the way to the thermosphere…"

Chrome furrowed his eyebrows, like he was trying to figure out all this aeronautical engineering nonsense Senku was spouting. After a few moments though, he gave up trying to decipher it himself.

"I...don't follow."

"It's just rocket science," Senku said matter of factly.

After a few moments he realized what he had just said and laughed a little. He wondered briefly if Chrome had ever heard that expression before. Then he continued.

"The engine works like pressure reaction on steroids," Senku said. "The oxidation of aluminum via ammonium perchlorate creates things like aluminum oxide, aluminum chloride, nitrogen gas, and most importantly water vapor. Because of the heat inside the engine, the water vapor and nitrogen expand which creates thrust."

"Thrust," Chrome repeated, "Upwards? So the rocket is going vertically, not across land like the gorilla car? Like the hot air balloon."

"Bingo, ten billion points to you," Senku smirked. "Because the solid engines have lower specific impulse, compared to liquid engines they give off thrust in a shorter time, which means that the reaction is way more powerful. So not only will it gain altitude faster but it can go about two hundred times further."

"A-awesome..." Chrome gawked.

Senku wasn't so sure that this rocket would live up to past ones, in fact he was almost sure it wouldn't, but it was a step forward. And he supposed for people like Chrome and Suika it would be the first time they'd ever seen something like it. So in that sense, he supposed it was enough for now.

"I might be jumping the gun a little," he said, smiling, "Space travel is a long way off from where we are but—but I just couldn't help myself…"

"Senku," Chrome was quiet for a moment. "Well, I can't wait to see it. And just a heads up, Suika is telling everyone so you'd better expect a bit of an audience."

"I figured," Senku smiled. "I'm almost finished, so go ahead and gather everyone."

"You got it!" Chrome shouted.

And once again Senku was left alone. He really hadn't noticed how much things had changed; how his experiments were less of impulse, less to show off and more to inspire. He wanted to inspire people like Chrome, because it takes more than one genius to make any sort of progress. Granted, Senku could get pretty far on his own, but he knew how to rely on others.

He knew the importance of people.

Senku relied on others to see things he missed, to look at the situation from a new perspective. It wasn't as if he was beyond error. Just like an experiment, the more eyes in play, the more trials done, the more experience gathered, the better the results. That was basic science. And he couldn't argue with science.

(Don't get me wrong, he still liked to show off. He loved to impress people with the power of science. He liked the inspiration in Chrome's eyes every time he invented something, or the awe in everyone else's when it all started to work. So, of course he was a bit of a show off. In the end, you see, it doesn't matter how great his invention is if there's no one to share it with. Genius needs an audience, after all.)

He continued to fiddle with the rocket, checking the math again and running one more experiment before putting the engine together. Senku had never wanted something to work so bad in his life. All those other things were important, sure, and he wanted them to work too, but this…this was who he was.

Senku was a science enthusiast, no doubt. But at heart he would always be an astrophysicist. And those guys are completely bonkers, what with all their compulsive behavior and rocket chemistry. Because as addicting as science itself was, space was even more so. Out there, in the depths of the universe, that's where all the answers were. The answer to the question humanity has asked since the beginning of time—who wouldn't find it exhilarating?

He ached for the stars. He longed for the moment when one of his rockets finally carried an astronaut into space—and he couldn't wait to get to try it himself. Senku Ishigami was going to space, and even a complete restart of civilization wasn't going to stop him.

One could guess at his motives. Perhaps it made him feel closer to his father. Maybe he was searching for something, and he hoped it was out there in the void of space. Or maybe he liked the feeling of finally breaking through gravity with his own hands.

Or maybe, just maybe, there was no reason at all.

Perhaps he just wanted it for the sake of wanting it.

After all, the source of all science is just curiosity, and humanity's blatant disregard for limits, and that one person who was either completely mad or an absolute genius who says: well someone had to do it so why not me? Why not now?

"Why not now," Senku said. "No time like the present to start our race to space."

"Then let's see it, scientist," Gen was behind him. Senku jumped, and whirled around to face an entire population of people.

Suddenly he felt very much like he might choke. All these people were waiting for success, waiting for him. They wanted to see it. They wanted to see the hope for humanity, the rocket ship that would mean they had finally caught up. This was the bridge between the modern world and the stone one. And Senku was terrified.

It must have showed.

"Come on," Chrome said, "We believe in you."

"Yeah!" Taiju shouted, "You haven't let us down so far."

"Even if it doesn't work this time," Suika smiled, "We'll just try again, right?"

"Right," Senku nodded. Everyone smiled back at him. All these people gathered together in the name of science. He could have cried if it wasn't so illogical. _Thank you_, he thought.

He tied a piece of their flag around the rocket, then took the switch and turned back. "Alright! Here we go, the very first rocket ship of this new age. The kingdoms of science has just added space travel to its to do list!"

Senku took a breath.

Then another.

And he launched the rocket.

That familiar rumbling noise that Senku had heard so many times before was bursting forth. The engine ignited and plumes of smoke erupted from the rockets tail, and everyone held their breath and then—

Then the rocket was thrust into the air. It's path was a little shaky considering the flappy job he'd done on the fins, but it flew. It went up and up and up. Senku smiled. Most people were too startled to move, still holding their breath, eyes trained on the sky. The rocket kept climbing, until it was barely a tiny point above them. Then the explosion that Senku had been expecting lit up the sky. To the average person it looked like a firework. He closed his eyes. _Finally_, he thought.

There was a moment where the world held its breath.

Everyone cheered.

"It worked!"

"He made a rocket!"

"It really flew!"

"Huh," Senku said, "I guess it did make to the stratosphere." Gen had the audacity to look surprised, but Taiju looked like the rocket was everything he expected it to be.

"Just like back then, Senku," he said, "Though I'm pretty sure our last one still holds the high score for height." Senku laughed.

"We'll beat it next time."

"Next time."

The sun was gone by now, and Senku cracked his knuckles. The kingdom of science was officially on its way back to where the world had been. This was a big milestone, no doubt, though they still had tons of stuff to build before they truly got close to their goal. Science is never done.

On the plus side, he was far from bored now.

"Get excited," he said. "Because this is only the beginning. We're gonna make it all the way to space!"

"You really are something," Gen sneered. "Never celebrating, only rushing forward to the goal. Senku-chan, you really are a mad scientist."

"Only a little," Senku shrugged.

They spent the rest of the night celebrating. They ate all kinds of bread and Senku was finally able to make real ramen with wheat to use for noodles. The kingdom of science was on a streak of success. And everyone was fired up from the rocket, seemingly even more motivated to move towards the future than they'd been before. It was all thanks to the power of science.

But the astrophysicist sat quietly, thinking. Always thinking.

As previously realized, Senku is an addict. Science is dangerous like that. It will never be just one experiment, one test, one rocket, science will make you learn and build and grow until it consumes your very being. Tonight, he'd finally had his fix, but the fire raged on. The power of science continued to consume him with everything left to create and the exhilarating feeling it was going to leave behind.

And even though Senku had spent all day feeding his addiction, he wasn't satisfied. Astrophysicists are like that—not even all the stars in the universe would be enough. The world was in the palm of his hand, but the fabric of space was woven into his being and he would never stop pushing its limits. He wanted to go higher, further. More, more, _more._

He had just launched the very first rocket in the kingdom of science.

But all he could think about was the next one he was going to build, how much better he was going to make it, and how much further there was left to go. Astrophysics was his obsession. Even after all those years it hadn't dulled one bit. It swallowed him whole, and Senku dove in head first.

Oh how the plights if addiction ailed him.

And oh how he wouldn't trade it for anything.


End file.
